Remove the file name from the comment at top of many files. In most
cases the file name was wrong anyway, so it's rather pointless.

Also unify the IBM copyright statement. We did have a lot of sightly
different statements and wanted to change them one after another
whenever a file gets touched. However that never happened. Instead
people start to take the old/"wrong" statements to use as a template
for new files.
So unify all of them in one go.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>

Use a sigp sense running to decide which signal processor order to use
for an ipi. If the target cpu is running use external call, if the target
cpu is not running use emergency signal.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Remove outdated bits from the initial cr0 register.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Do not set the cr0 enablement bit for iucv by default in head[31|64].S,
move the enablement to iucv_init in the iucv base layer.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

The alignment is missing for various global symbols in s390 assembly code.
With a recent gcc and an instruction like stgrl this can lead to a
specification exception if the instruction uses such a mis-aligned address.

Specify the alignment explicitely and while add it define __ALIGN for s390
and use the ENTRY define to save some lines of code.
Signed-off-by: NJan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

As of git commit 1844c9bc head64.S/head31.S
are not included in head.S anymore but build as an extra object. This breaks
shared kernel support because the .org statement in head64.S/head31.S for
CONFIG_SHARED_KERNEL=y will have a different effect. The end address of the
head.text section in head.o will be added to the .org value, to compensate
for this subtract 0x11000 to get the required value of 0x100000 again.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Fix two bugs with the kernel image compression:
1) reset the bss section of the compressed vmlinux
2) clear the high half of the registers for 64 bit early enough
   for the decompression step
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Add the "bzImage" compile target and the necessary code  to generate
compressed kernel images. The old style uncompressed "image" target
is preserved, a simple make will build them both.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Remove support to be able to dump 31 bit systems with a 64 bit dumper.
This is mostly useless since no distro ships 31 bit kernels together
with a 64 bit dumper.
We also get rid of a bit of hacky code.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

When the kernel is IPLed without the CLEAR option and switches
to 64-bit, the high-order half of the registers might contain
random values.  This can cause addressing exceptions and the
kernel enters an interrupt loop.

Initialize the high-order half of the general purpose registers
with zeros after switching to 64-bit mode.

Cc: <stable@kernel.org>
Signed-off-by: NHendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Saves us more than 65k pointless IPIs.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

"lockdep: Fix backtraces" reveales a bug in early setup code: when
lockdep tries to save a stack backtrace before setup_arch has been
called the lowcore pointer for the current thread info pointer isn't
initialized yet.
However our save stack backtrace code relies on it. If the pointer
isn't initialized the saved backtrace will have zero entries.
lockdep however relies (correctly) on the fact that that cannot
happen.
A write access to some random memory region is the result.

Fix this by initializing the thread info pointer early.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

The extract cpu time instruction (ectg) instruction allows the user
process to get the current thread cputime without calling into the
kernel. The code that uses the instruction needs to switch to the
access registers mode to get access to the per-cpu info page that
contains the two base values that are needed to calculate the current
cputime from the CPU timer with the ectg instruction.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Early init code clears the backchain of the initial kernel stack frame.
This is not necessary since it is pre initialized with zeros. Plus it
was broken on 64 bit since it cleared only four of eight bytes.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

This patch adds the code generation option for IBM System z10 and
adds a check in head[31,64].S to prevents the execution of a kernel
compiled for a new processor type on an old machine.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

This adds hugetlbfs support on System z, using both hardware large page
support if available and software large page emulation on older hardware.
Shared (large) page tables are implemented in software emulation mode,
by using page->index of the first tail page from a compound large page
to store page table information.
Signed-off-by: NGerald Schaefer <geraldsc@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

From: Heiko Carstens <heiko.carstens@de.ibm.com>
From: Carsten Otte <cotte@de.ibm.com>

This lets us use defines for the magic bits in machine flags instead
of using plain numbers all over the place.
In addition on newer machines features/facilities are indicated by the
result of the stfl instruction. So we use these bits instead of trying
to execute new instructions and check wether we get an exception or
not.
Also the mvpg instruction is always available when in zArch mode,
whereas the idte instruction is only available in zArch mode. This
results in some minor optimizations.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NCarsten Otte <cotte@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

The clear-by-asce operation of the idte instruction gets an asce
(address-space-control-element) as argument to specify which TLBs
need to get flushed. The current code passes a plain pointer to
the start of the pgd without the additional bits which would make
the pointer an asce. The current machines don't mind the difference
but a future model might want to use the designation type control
bits in the asce as a filter for the TLBs to flush.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

s390 machines provide hardware support for creating Linux dumps on SCSI
disks. For creating a dump a special purpose dump Linux is used. The first
32 MB of memory are saved by the hardware before the dump Linux is
booted. Via an SCLP interface, the saved memory can be accessed from
Linux. This patch exports memory and registers of the crashed Linux to
userspace via a debugfs file. For more information refer to
Documentation/s390/zfcpdump.txt, which is included in this patch.
Signed-off-by: NMichael Holzheu <holzheu@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>

Replaced check_user_space() + __check_access_register with the new
check_space(). The old functions made wrong assumptions about kernel
and user space when the kernel and user address spaces are switched
(kernel in home space, user in primary/secondary space).
Secondly the user process can switch to the accress register mode if
it is running in primary or secondary mode. In addition it can load
an arbitrary value to the access registers. If any other value than
0 for primary space or 1 for secondary space is loaded and memory
is accessed using the base register related to the access register,
the program should be terminated with a SIGSEGV. To achieve that the
DUALD pointer in the DUCT and the PSALD pointer in the PASTE need
to point to an array of 8 invalid access-list entries to get a
ALEN-translation exception if an invalid alet is used.
Signed-off-by: NGerald Schaefer <geraldsc@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

With CONFIG_SHARED_KERNEL the kernel text segment that might be in a
read only memory sections starts at 1MB. Memory between 0x12000 and
0x100000 is unused then. Free this, so we have appr. an extra MB
of memory available.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Hopefully this will make it more maintainable and less error prone.
Code makes use of search_exception_tables(). Since it calls this
function before the kernel exeception table is sorted, there is an
early call to sort_main_extable().

This way it's easy to use the already present infrastructure of fixup
sections. Also this would allows to easily convert the rest of
head[31|64].S into C code.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Add support to boot from a named saved segment (NSS).
Signed-off-by: NHongjie Yang <hongjie@us.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

FCP dump feature detection works only if the sclp command in head.S
was succesful. Since the sclp command is skipped if diag260 works,
we don't have any dump feature detection anymore.
Bug was introduced with d57de5a3.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Fix a memory leak problem in the memory detection routines.  A memory leak
of 128k occurs when we have a contiguous memory with mixed access-mode
(read or write) ranges.
Signed-off-by: NHongjie Yang <hongjie@us.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

VMALLOC_END on 31bit should be 0x8000000UL instead of 0x7fffffffL.
The page mask which is used to make sure memory_end is on 4MB/2MB
boundary is wrong and not needed. Therefore remove it.
Make sure a vmalloc area does also exist and work on (future)
machines with 4TB and more memory.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Avoid the tprot loop if diag260 works and reports that there are no
holes in memory. The tprot instruction can lead to a significant delay
in the ipl process if the virtual guest has a lot of memory and the
host is under memory pressure.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>

Use the new diagnose 0x9c in the spinlock implementation for s390.  It
yields the remaining timeslice of the virtual cpu that tries to acquire a
lock to the virtual cpu that is the current holder of the lock.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Huge s390 assembly files whitespace cleanup.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

This introduces new user-copy operations which are optimized for
copying more than 256 Bytes on new hardware.
Signed-off-by: NGerald Schaefer <geraldsc@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Convert GET_IPL_DEVICE assembler macro to C function.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

It is now possible to specify a ccw/fcp dump device which is used to
automatically create a system dump in case of a kernel panic. The dump
device can be configured under /sys/firmware/dump.
In addition it is now possible to specify a ccw/fcp device which is used
for the next reboot of Linux. The reipl device can be configured under
/sys/firmware/reipl.
Signed-off-by: NMichael Holzheu <holzheu@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Move initrd if the bitmap of the bootmem allocator would overwrite it.
In addition this patch sets the default size and address of the initrd to 0.
Therefore all boot loaders must set the initrd size and address correctly.
This is especially relevant for ftp boot via HMC/SE, where this change
requires a special patch file entry in the .ins file which sets these two
values contained at address 0x10408 and 0x10410.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

SLES9 binutils don't like .align 4096 statements in head.S. Work around this
by using .org statements.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

There is almost no room left for any new code between 0x10000
and 0x10480. Move the code from 0x10000 to 0x11000.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

The wrong base register is used to read a value from the sclp data
structure. The value is used to calculate the memory size.
Use correct register %r4.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Merge common parts of head.S and head64.S into head.S and move architecture
specific parts to head31.S and head64.S respectively.  Saves us ~500 lines
of duplicated assembly code.
Acked-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Don't switch back to 24 bit addressing mode when waiting for an external
interrupt and set the correct bit in wait PSW (external mask instead of I/O
mask).
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>